microbiology an introduction test bank

Correct Answer: A

Rationale: The correct answer is A: chronic. A persistent infection that is not lytic but productive is characterized by ongoing viral replication without cell lysis. This type of infection is referred to as chronic, as it persists over an extended period. Latent infections involve periods of dormancy with intermittent reactivation. Slow infections typically have a prolonged incubation period before causing symptoms. Transforming infections lead to permanent alterations in host cell behavior. The key distinction for this question is the continuous viral replication without cell destruction, which aligns with the definition of a chronic infection.

Correct Answer: A

Rationale: Exotoxins are proteins produced inside the microbe cell and then released outside the cell to exert their toxic effects on neighboring cells or tissues. This is why choice A is correct. Choices B and C are incorrect because exotoxins are not meant to act within the same cell they are produced in. Choice D is incorrect because exotoxins are usually released without causing cell lysis; they are secreted by the microbe actively rather than being leaked out due to cell damage.

Correct Answer: C

Rationale: The correct answer is C: Fungi. Molds are a type of fungi, which are eukaryotic organisms characterized by having cell walls made of chitin. Fungi are distinct from protozoans (single-celled eukaryotes), archaea (prokaryotes), and algae (photosynthetic eukaryotes). Fungi, including molds, obtain nutrients through absorption and play crucial roles in decomposition and nutrient cycling. Therefore, molds belong to the group of eukaryotic organisms known as fungi.

Correct Answer: D

Rationale: The correct answer is D: Proteus vulgaris. This is because Proteus species are non-lactose-fermenting, Gram-negative rods that produce gas in nutrient broth. They are known to cause severe abdominal pain due to their ability to invade the intestinal mucosa. A: Salmonella enterica is a lactose-fermenting organism and typically does not produce gas in nutrient broth. B: Shigella dysenteriae is a lactose-negative organism but does not produce gas in nutrient broth. C: Escherichia coli is a lactose-fermenting organism and does not typically produce gas in nutrient broth. In summary, the presence of non-lactose-fermenting, gas-producing Gram-negative rods points towards Proteus vulgaris as the most likely causative agent of the severe abdominal pain.

Correct Answer: C

Rationale: Rationale: 1. Psychrophilic: Grow best in cold temperatures 2. Mesophilic: Grow best in moderate temperatures 3. Thermophilic: Grow best in high temperatures - Choice A is incorrect as "thermophobic" is not a recognized term. - Choice B is incorrect as "psychophobic" is not a recognized term. - Choice D is incorrect as "mesophobic" is not a recognized term.